"I went to the main street at about 0400am and it was like a screen from a zombie movie: cars were in the middle of the street, buildings had caved in and there was no light and no-one else around," he said.

On Sunday, some 5,000 residents in the Hunter Valley were ordered to leave their homes amid fears that the Hunter River would breach its levee within hours.

In the Newcastle suburb of Wallsend, where 200mm of rain fell in a few hours, state premier Morris Iemma warned that the risk was not yet over.